Distribution

In all of the following figures, values where the scheduled collection time occured > 1 hour prior to the order time were removed (n = 44). It is unclear exactly why the the scheduled collection time for these orders was back-dated to be prior to the time of ordering.

It is clear that Stat orders dispatch immediately, but Routine and Timed Study are much more variable, with most dispatching 1-3 hours before the scheduled collection time.

Summary measures for the time from dispatch to scheduled collection

type	category	minimum	q1	median	mean	q3	maximum	na
All	All	-3.017	0.000	0.783	1.709	1.783	33.550	33
Future	All	-2.250	0.783	1.767	2.577	2.283	33.550	16
Future	Routine	-2.250	0.250	1.117	2.607	3.242	23.800	6
Future	Stat	-0.083	2.000	4.867	7.218	11.150	24.280	NA
Future	Timed Study	0.017	0.879	1.767	2.272	2.267	33.550	10
Now	All	-3.017	-0.017	-0.017	-0.026	0.000	0.917	17
Now	Routine	-3.017	-0.800	-0.333	-0.502	-0.033	0.817	6
Now	Stat	-0.800	-0.017	-0.017	0.000	0.000	0.917	7
Now	Timed Study	-0.483	0.000	0.217	0.292	0.633	0.917	4

Future Orders

Day of week and hour of day are based on the scheduled collection time.

Control Charts

Correlation Assessment

There is a strong correlation between the time from order to scheduled collection and the time from order to dispatch.

Correlation between the time from order to scheduled collection and the time from order to dispatch

type	category	estimate	statistic	p.value	parameter	conf.low	conf.high	method	alternative
All	All	0.991	410.997	0.000	3224	0.990	0.991	Pearson’s product-moment correlation	two.sided
Future	All	0.991	339.529	0.000	2149	0.990	0.992	Pearson’s product-moment correlation	two.sided
Future	Routine	0.996	289.329	0.000	640	0.996	0.997	Pearson’s product-moment correlation	two.sided
Future	Stat	0.277	2.692	0.009	87	0.073	0.459	Pearson’s product-moment correlation	two.sided
Future	Timed Study	0.972	154.543	0.000	1418	0.969	0.974	Pearson’s product-moment correlation	two.sided
Now	All	-0.008	-0.276	0.783	1073	-0.068	0.051	Pearson’s product-moment correlation	two.sided
Now	Routine	0.034	0.408	0.684	143	-0.130	0.196	Pearson’s product-moment correlation	two.sided
Now	Stat	0.134	3.766	0.000	775	0.064	0.202	Pearson’s product-moment correlation	two.sided
Now	Timed Study	0.264	3.363	0.001	151	0.110	0.406	Pearson’s product-moment correlation	two.sided

There is little correlation between the time from order to scheduled collection and time from dispatch to scheduled collection. This suggests that the dispatch time is triggered by the scheduled collection time, regardless of how far in advance the lab is ordered, with the exception of Stat orders which dispatch immediately.

Correlation between the time from order to scheduled collection and time from dispatch to scheduled collection

type	category	estimate	statistic	p.value	parameter	conf.low	conf.high	method	alternative
All	All	0.238	13.907	0.000	3224	0.205	0.270	Pearson’s product-moment correlation	two.sided
Future	All	0.115	5.381	0.000	2149	0.073	0.157	Pearson’s product-moment correlation	two.sided
Future	Routine	0.126	3.206	0.001	640	0.049	0.201	Pearson’s product-moment correlation	two.sided
Future	Stat	0.921	22.059	0.000	87	0.882	0.948	Pearson’s product-moment correlation	two.sided
Future	Timed Study	0.182	6.950	0.000	1418	0.131	0.231	Pearson’s product-moment correlation	two.sided
Now	All	0.613	25.396	0.000	1073	0.574	0.649	Pearson’s product-moment correlation	two.sided
Now	Routine	0.290	3.623	0.000	143	0.133	0.433	Pearson’s product-moment correlation	two.sided
Now	Stat	0.968	106.808	0.000	775	0.963	0.972	Pearson’s product-moment correlation	two.sided
Now	Timed Study	0.987	74.553	0.000	151	0.982	0.990	Pearson’s product-moment correlation	two.sided

There is no correlation between the amount of time prior to scheduled collection that the task dispatched and when the lab was actually collected.

Correlation between the amount of time prior to scheduled collection that the task dispatched and when the lab was actually collected

type	category	estimate	statistic	p.value	parameter	conf.low	conf.high	method	alternative
All	All	-0.079	-4.210	0.000	2804	-0.116	-0.042	Pearson’s product-moment correlation	two.sided
Future	All	-0.103	-4.405	0.000	1827	-0.148	-0.057	Pearson’s product-moment correlation	two.sided
Future	Routine	-0.049	-1.180	0.238	578	-0.130	0.033	Pearson’s product-moment correlation	two.sided
Future	Stat	0.151	1.373	0.173	81	-0.067	0.355	Pearson’s product-moment correlation	two.sided
Future	Timed Study	-0.170	-5.870	0.000	1164	-0.225	-0.113	Pearson’s product-moment correlation	two.sided
Now	All	-0.251	-8.081	0.000	975	-0.308	-0.191	Pearson’s product-moment correlation	two.sided
Now	Routine	-0.285	-3.342	0.001	126	-0.437	-0.118	Pearson’s product-moment correlation	two.sided
Now	Stat	-0.072	-1.943	0.052	718	-0.145	0.001	Pearson’s product-moment correlation	two.sided
Now	Timed Study	-0.094	-1.067	0.288	127	-0.263	0.080	Pearson’s product-moment correlation	two.sided

Back-Dated Orders

Future Orders

A large number of Routine orders (81%) were actually intended as future timed orders.